Vehicle DC voltage conversion circuit

Abstract

This application provides a vehicle DC voltage conversion circuit, including a high voltage battery connected in sequence, a primary-side-bridge module, a resonant module, a transformer module and a secondary-side-output module, wherein the secondary-side-output module includes a first voltage unit outputting a first voltage and a second voltage unit outputting a second voltage. The secondary side winding of the transformer is connected with the first voltage unit and the second voltage unit; The circuit also includes a driver module connected with the original side bridge module. The vehicle DC voltage conversion circuit provided in this application can not only output the first voltage, but also output the second voltage at the same time. It has the advantages of small size, high efficiency, low cost and industrialization, and can be widely used in the vehicle 48V electrical load, such as 48V vehicle electric heating system, 48V vehicle cooling fan, and so on.

What is claimed is: 
     
       1. A vehicle DC voltage conversion circuit, characterized by comprising a high-voltage battery, a primary-side-bridge module, a resonance module, a transformer module, and a secondary-side-output module connected in sequence, wherein the secondary-side-output module comprises a first voltage unit configured to output a first voltage output module and a second voltage unit configured to output a second voltage, secondary winding of the transformer module is connected to the first voltage unit and the second voltage unit respectively;
 the circuit further comprising a drive module connected with the primary-side-bridge module; the primary-side-bridge module comprising a plurality of primary side half bridges connected to each other, each primary side half bridge comprising two switch elements connected in series; the drive module is respectively connected to the control end of each switch element of the primary-side-bridge module, to control the on-off of the switch element of the primary-side-bridge module; and 
 wherein the transformer module comprises a secondary winding with a center tap, the center tap and the secondary non-inverting end and/or the secondary inverting end of the secondary winding are connected to a first voltage circuit of the first voltage unit: the secondary non-inverting end and the secondary inverting end of the secondary winding are connected to a second voltage circuit of the second voltage unit. 
 
     
     
       2. The circuit according to  claim 1 , characterized in that, the primary-side-bridge module comprises a first half bridge and a second half bridge connected in series, and the first half bridge comprises a first switch element and a second switch element connected in series, the second half-bridge comprises a third switch element and a fourth switch element connected in series, a common end of the first switch element and the second switch element is connected to the resonance module, and the common end of the fourth switch element and the third switch element is connected to the resonance module. 
     
     
       3. The circuit according to  claim 2 , characterized in that, the resonance module comprises a first resonance unit and a second resonance unit, the first resonance unit comprises a first inductor, a first capacitor, and a second capacitor, and the second resonance unit comprises a second inductor, a third capacitor, and a fourth capacitor, the transformer module comprises a first transformer and a second transformer;
 the first switch element, the second switch element, and the third switch element and the fourth switch element are connected in series between a positive bus bar and a negative bus bar of the high-voltage battery in sequence, and the common end of the first switch element and the second switch element is connected to a first end of the first inductor, the common end of the third switch element and the fourth switch element is connected to a first end of the second inductors; 
 a second end of the first inductor is connected to a primary non-inverting end of the first transformer, a second end of the second inductor is connected to a primary non-inverting end of the second transformer; 
 the first capacitor, the second capacitor, the third capacitor, and the fourth capacitor are connected in series between the positive bus bar and the negative bus bar in sequence, a common end of the second capacitor and the third capacitor is connected to the common end of the second switch element and the third switch element, the common end of the first capacitor and the second capacitor is connected to a primary inverting end of the first transformer, and a common end of the third capacitor and the fourth capacitor is connected to a primary inverting end of the second transformer. 
 
     
     
       4. The circuit according to  claim 2 , characterized in that, the first switch element, the second switch element, the third switch element, and the fourth switch element are selected from at least one of MOS field effect transistors, junction field effect transistors, transistors and relays. 
     
     
       5. The circuit according to  claim 1 , characterized in that, the first voltage circuit comprises a fifth switch element and a fifth capacitor, and an output end of the fifth switch element is connected to the secondary non-inverting end or the secondary inverting end, and the fifth capacitor is connected between an input end of the fifth switch element and the center tap. 
     
     
       6. The circuit according to  claim 5 , characterized in that, the first voltage circuit further comprises a sixth switch element, an input end of the sixth switch element is connected to the input end of the fifth switch element, and the secondary non-inverting end and the secondary inverting end are respectively connected to one output end of the sixth switch element and the fifth switch element. 
     
     
       7. The circuit according to  claim 6 , characterized in that, the fifth switch element and the sixth switch element are selected from at least one of diodes, MOS field effect transistors, junction field effect transistors, transistors, and relays. 
     
     
       8. The circuit according to  claim 1 , characterized in that, the second voltage circuit comprises a seventh switch element, an eighth switch element, a seventh capacitor, and an eighth capacitor; the output end of the seventh switch element is connected to the positive pole of the second voltage, the input end of the eighth switch element is connected to the negative pole of the second voltage, and an input end of the seventh switch element and an output end of the eighth switch element are connected to the secondary non-inverting end; the seventh capacitor and the eighth capacitor are connected in series between the positive and negative pole of the second voltage, and a common end of the seventh capacitor and the eighth capacitor is connected to the secondary inverting end. 
     
     
       9. The circuit according to  claim 1 , characterized in that, the transformer module comprises a first transformer and a second transformer, a first secondary winding of the first transformer is provided with a first center tap, and a second secondary winding of a second transformer is provided with a second center tap:
 the first voltage unit comprises a first-first voltage circuit and a first-second voltage circuit outputting in parallel, the first center tap and the secondary non-inverting end and/or the secondary inverting end of the first secondary winding are connected to the first-first voltage circuit, and the second center tap and the secondary non-inverting end and/or the secondary inverting end of the second secondary winding are connected to the first-second voltage circuit; 
 and/or, the second voltage unit comprises a second-first voltage circuit and a second-second voltage circuit outputting in parallel, and the secondary non-inverting end and the secondary inverting end of the first secondary winding are connected to the second-first voltage circuit, and the secondary non-inverting end and the secondary inverting end of the second secondary winding are connected to the second-second voltage circuit.